After wasting a handful of first-half chances while living dangerously in their own half, Hirving Lozano’s 35th-minute strike on the break proved just reward.
Serbia had dominated against a Costa Rica side who rarely threatened after a bright start, but chances were thin on the ground until Kolarov made the breakthrough in the 56th minute.
Turkey’s President Tayyip Erdogan had said on Saturday that Turkish warplanes had struck a meeting of the outlawed PKK in Qandil, where he believed high-profile militants had been hit.
The hosts face the north Africans in St Petersburg on Tuesday and defeat would almost certainly condemn Egypt to an early exit.
Kim Kardashian West's late father was "heavy on [her] mind" the night before Father's Day.
Francis made the comparison in a long, off-the-cuff address to a members of a confederation of Italian family associations.
Looking relaxed and contented at a news conference, the Uruguay players dismissed concerns about the toll on them from gruelling flights from South America and around Russia.
The taxi drove into a crowd of pedestrians near the Kremlin and injured seven, including two Mexicans visiting the city for the soccer World Cup, which Russia is hosting.